From 150 lbs she is down to 105.
She lives in a lovely apartment.
Her kitchen is well stocked, she eats a healthy breakfast at home .
She goes out to eat regularly and often orders a chocolate milkshake after a generous, well balanced meal.
Yet she continues to lose weight.
She is generally active, using a walker to shop and do errands with her companion.
The companion is taking on more housecleaning duties but she still does her own laundry and changes her sheets and straightens up her apartment.
She does have arthritis and a colostomy.
Her heart is strong and though she has fallen a few times she has never broken a bone!
She knows what she likes and what she wants and is demanding, usually getting it.
Are you sure she is eating the food and not eating and throwing it up? or eating and having diarrhea? or worse, acting like she is eating but actually tossing the food because it didn't taste good? Does #2 (output from the body) align with the amount of food that she is taking in?
Assuming none of the above is happening, I agree, it is time for a full blood panel analysis. Make sure they check for thyroid which is an "extra" test.
In addition, I have read (and do believe) that the "elderly" body is not as efficient at absorbing nutrients from food, some bodies more than others. That is why the suggestion of taking a daily multi-vitamin and especially vitamin D and/or vitamin B12 supplement. However, a complete blood panel analysis would be able to point out any known vitamin deficiencies.
Is she seeing a doctor for an annual or bi-annual? Has the doctor commented on the change in weight?
We now have "Pie Lunch Wednesdays"!
My mom still knows how to use an oven and microwave. I often "let" her cook lunch for the 2 of us, because it's helpful to her to feel as if she's useful in some way. Also, I keep her fridge and pantry stocked with everything from fresh organic veggies to cake and ice cream, in order to tempt her failing appetite.
One thing I learned from watching my dad die -- throw out the diet cookbooks at the end! The important thing is just to get them to eat something...no matter whether it's "health" food or not.
I hate Dementia too. It's become my Nemesis.
Weight loss, when not purposely dieting, can be due to a number of illnesses, some of them very serious.
My 91 year old mom has gone from 145 lbs to 113 in one year. She also has a well stocked pantry, freezer and refrigerator and generally shows a normal appetite when eating around others.
Still, I'm worried, and I've taken her to the doctor twice so far since beginning caretaking earlier this year. So far, everything checks out ok physically; mentally, it's apparent to everyone that Mom's in the early to mid stages of Alzheimers.
Best of luck